Area of triangles

Key Notes :

🌟 Area of Triangles

🔹 What is Area?

• The area of a shape is the amount of surface it covers.
• It is measured in square units (like cm², m², etc.).

🔺 Formula for the Area of a Triangle

Area=1/2×base×height

✅ Base (b): The bottom side of the triangle.

✅ Height (h): The perpendicular distance from the base to the opposite vertex.

📘 Examples

Example 1:

If base = 10 cm and height = 8 cm

Area=1/2×10×8=40 cm²

Example 2:

If base = 12 m and height = 5 m

Area=1/2×12×5=30 m²

✨ Area of Special Triangles

a) Equilateral Triangle

All sides are equal.

Area=√3/4×side²

b) Isosceles Triangle

Two sides are equal. Use base and height (found using Pythagoras theorem if needed).

c) Right-Angled Triangle

The two shorter sides are base and height.

Area=1/2×(product of the two shorter sides)

📏 Units of Area

Measurement	Unit of Area
centimetres (cm)	square centimetres (cm²)
metres (m)	square metres (m²)
kilometres (km)	square kilometres (km²)

🧮 Area Using Heron’s Formula

If the triangle’s sides are a, b, c and height is not known:

s=(a+b+c)/2

​ Area=√s(s−a)(s−b)(s−c)

👉 Useful when only the lengths of the sides are given.

💡 Important Points

• ⭐ Base and height must be perpendicular to each other.
• ⭐ Area is always positive.
• ⭐ Always write the unit after the answer.

🧠 Quick Tip

To remember the basic formula:

“Half of base times height — gives area just right!” 😄

Learn with an example

Let’s practice!🖊️